Dear M. Gregg as you say, there are solid amplifiers-sounding as good as TCA and tube. Accordingly, it is also possible to make a digital emulation process. Then just insert your finger. You just need to know how to build and what to add or subtract, does it?
To explain the difference in their sound, I need to reveal part of the theory and separately address matters of dynamic stability of various types of systems. This somewhat contradicts the issue.
Best regards, Sergey
To thoglette -Class d-technical aspect of implementation, not more than, the same as any other and, B, ... Audio fidelity is not the plane.
I am sorry if that is not clear, I have running program iTranslate for iPad

All of these have been listed as "not your usual silicon AB amp" or "sounds like a good valve amp" by more than one person. Any other candidates?

I should add Papa Nelson Pass's amps to this list, I've heard and built a few Zen style amps (and a Pass Aleph) and it's probably time to return one to the stable.

Along with favorite, personal amps by Doug Self and Marshall Leach. But as I've been watching the progress of Hugh Dean along the line of "linearity first" for many years that's where my next AB amp will come.

Any other candidates, yes mine where it was likened to a KT88 amp (post #186).

Great job. Always when the ask based on what benchmarks are being developed, you get a ton of great examples. In the end come back to the comparative analysis of good-bad, but there is a solution for outstanding audio performance. Simple indeed and any complexity in realization depending on the application. More or less distortion, is irrelevant to the fidelity of sound, where all embedded emotions.Less of course better
If the sound field of a source as a hologram, judging by the results of listening, not so easy to mess up the final, any links of the amplification circuit.

Can you tell the difference with an old valve amp against a trainsistor or fet amp if you can't see it..I have found that sometimes a tube amp can sound like an old "not very good" transistor amp it depends on a lot of factors..

Can you tell the difference between a fet stage driving an output Tx and a tube amp?

Even Tim De paravicini said he made a FET version of his high end amp and said it was just as good. I think it was the Yoshino..

But then again whats the point of a SS amp that sounds like a tube amp (except for guitar) if most people are saying the valve is adding distortion..Perhaps different distortion to a transistor circuit..

The same is true for both types with types of PSU (choke or other)..

Regards
M. Gregg

I think the last commercial valve amps and the better transistor designs of the same era did sound very similar . Some designers went to a lot of trouble to ensure that ( Leak ) . What astonishes me is how little respect there is for the better 1960's transistor designs . No one seems to like them much . I have to say the Leak Delta 30 was so much better than anything I heard before . I was stunned and had to find new ways of understanding how to listen when using one . It lacked nothing . Nothing I have heard since has surprised me as much except a proper Williamson. Slightly sterile , more so than the Delta 30 . Give the Delta a better bias design and a set of 3055's and surprise yourself . If the receiver you will be delighted .

The Leak was especailly nice looking as the Wharfedale Linton amp .

Sidney Smith who I knew briefly said one day he hoped people would do up his transistor designs . He said in a slightly sad voice he was convinced they were as good .

That would explain why I have difficulty understanding what you write. When you publish your theory please write it in Russian then get a friend to translate it into English.

Well, then a more complicated part. How is adherence to the current of the transistor for current signal? How long (Delta faza) full synchronization occurs? What are the frequency of synchronization boundary within which it occurs without the doubling period.
There is a more simple and clear explanation, it does not cite
I have already apologized for the difficulties of translation, I can write in russian, but it's hardly a lot will change.

Mr Kron whose wife mistook me for someone who owed them $20 000 ( far too long to tell ) . She sat me down with the late Ricardo . Richardo dryly said to me " what is all this valve nonsense , surly transistors are better " ? . I smiled and said , absolutely . Without hesitation he continued " I made the best ever 300 B ( ? or was it 211 ? ) , it looked different as the heater was an advanced design , I couldn't give them away " . I shorten it a bit . He was sad that tradition more than better design mattered .

If you read up on this A2 design you will see the assertion that class A2 has some rather wonderful distortion qualities . Others say can sound good if careful , Who knows ?

So don't try to venture a complicated discussion.
Try to believe in the word, there is an easy solution, with further complicated evidence and parsed.
And it can have a huge impact on all further work in the field of audio and related.
The question whether this is? And how to implement this feature.